Page 891 - Cable Stayed Bridge News Today

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By wednesday and thursday in the south bay. >> thats going to feel good. "nbc nightly news" is next. then more local news here at 6:00. hope you can join us. on this sunday night, the big dig out. cleaning up after the massive, deadly storm that dumped record-breaking amounts of snow, flooded people out of their homes and left millions stranded. tonight, our in-depth coverage of the blizzard that paralyzed the east coast and left its mark on history. final push. the candidates running hard i...

♪ it may look like special effects from an old hollywood movie, but this is real. a massive steel and concrete bridge sways and buckles, leaving commuters desperate to escape before it collapses. >> it was breathtaking. it was frightening. >> november 7th, 1940, tacoma, washington.

>> another person trying to escape from the bridge that day is professor bert farquharson. >> professor bert farquharson was a professor of engineering at the university of washington and he was an authority on bridge structures. so when eldridge and lacey murrow became concerned about how much this bridge might move, they hired bert farquharson to conduct some studies. >> as part of his study, dr. farquharson sets up film cameras a few weeks after the bridge opens to capture its movements. seve...

The suspender cables that went from the bridge deck to the main suspension cable itself began to snap. >> and then the unimaginable happens. the massive steel structure bends, whips and contorts so violently that it collapses into the rushing water below. both make it off the bridge alive, but not tubby. hes still in the backseat of the studebaker when the structure gives way. the bridge failure makes news all across the world. >> the tacoma narrows bridge dedicated in 1940 was the pride of the ...

The motion could be fairly dramatic. >> but some find that wave-like motion harrowing. >> as you drove across the bridge, you could look ahead and the car in front of you maybe 100 yards would absolutely disappear as you went down into the bottom of one of these troughs. it was unnerving to a lot of drivers. many who crossed the bridge swore it would be the last time. and on that windy autumn day in 1940, it is the last time anyone crosses that bridge. >> about 10:00, the bridge began to move ...

And many of the things that exist on the 1950s bridge are a tribute to better aerodynamic stability. >> in 2007, a twin bridge is completed. the architectural look of both structures resembles the original gertie, a tribute to her grace and elegance. >> so that new bridge, as well as others have been constructed since 1940, are part of galloping gerties legacy. coming up -- an iceberg implodes in front of a group of tourists, sending them scrambling for safety. >> were all shouting and screami...

Its a blustery day in puget sound, located in the northwest section of the evergreen state. winds are gusting a little more than 40 miles per hour, causing the tacoma narrows bridge to really sway. surprising as it looks, the movement doesnt stop cars and pedestrians from crossing it. ever since the bridges opening four months earlier, residents affectionately call her galloping gertie because of the way she dances and snakes in the wind. bridges are designed to move a little, but gerties moveme...

It dit literally shook itself to pieces. >> very early in the process, in fact before construction began, the lead engineer was very concerned about the bridge, so he began to help initiate studies by the professor at the university of washington that began to closely examine the bridges movements. >> remedies are attempted before and after the bridge opens. >> they added cable tie downs at each end of the bridge on the approach spans. they did a good job of holding the approach spans in place. ...

Tim moore, senior structural engineer for washingtons department of transportation says the cause of the collapse was torsional flutter or aerodynamic instability. >> that was the vice that took the bridge down. this was a condition that no structure can maintain for a significant period of time. >> gertie is replaced by a stronger bridge in 1950, ten years after the collapse. but a part of it still survives. >> this is the side span, the approach span. this is the original galloping gerties 194...